What Are Data Area Attributes?

Data area attributes in the data area deployment file (dataarea.xml) control many aspects of the data area configuration. The deployment file specifies attributes such as:

  • default values for each data area

  • the modules included in the data area

  • the database space assignment for the data area or its files

The following topics describe the data area attributes you can set for different components of the data area, using the changeda utility.

Default Attributes

Attributes set at the default level determine what values will be applied to any objects that do not have other, specific values assigned. The default attributes are the database space, the character set, whether to use split LOB storage, and whether to implement the primary index delete flag.

See Changing Default Data Area Attributes Using changeda.

Space Attributes

The space associates a name with a logical database space in a specific database type. The space name may be used in the Default, System and File entries, in order to associate objects with the space.

In addition to the database type, a space definition can specify a table space, index space, LOB space, and schema for a database object. Other attributes indicate whether the table is a view (non-Landmark table), what type of SQL code should be generated for the database object, what character set to use, whether to use split LOB storage, and whether to implement the primary index delete flag.

Multiple spaces may be defined in a single data area. Spaces may be assigned to different databases.

If no space entry exists in the file, all data area objects will be assigned to the empty database space.

See Changing Database Space Attributes Using changeda.

Module (System) Attributes

A database space for all files in a module can be assigned, and you can specify whether to use split LOB storage and whether to implement the primary index delete flag. If a space definition is not present for a given module within a data area, then the default space for the data area will be used for that module.

See Changing Module Attributes Using changeda.

File Attributes

You can specify a database space, whether or not variable characters are used for a single file. whether to use split LOB storage, and whether to implement the primary index delete flag.

These values override default values assigned at the higher levels of Module and Default.

See Changing Database File Attributes Using changeda.

Index Attributes

You can specify whether a physical index should be created.

These values override default values assigned at the higher levels of Module and Default.

See Changing Index Attributes Using changeda.

Column Attributes

For all or specified columns in a table or file, you can use changeda to specify a string containing DDL statements to be executed when changeda is run.

See Changing Column Attributes Using changeda.

Specifying Attributes Using Business Class Pattern Matching

You can specify a database space, whether or not variable characters are used, whether to use split LOB storage, and whether to implement the primary index delete flag for all business classes that include a specified LPL pattern.

Attributes specified using the BusclassPattern option will override specifications at the Default or System level. Attributes specified by FilePattern or specific File entries will override BusclassPattern entries.

See Changing File Attributes with Matching Business Class Patterns Using changeda.

Specifying Attributes Using File Name Pattern Matching

You can specify a database space,whether or not variable characters are used, whether to use split LOB storage, and whether to implement the primary index delete flag for all files whose names match a specified LPL file name. The File name match supports regular expressions.

See Changing File Attributes for File Names Matching a Pattern Using changeda.